OBU type/metadata disambiguation.

- OBU_TD => OBU_TEMPORAL_DELIMITER
- METADATA_TYPE => OBU_METADATA_TYPE
- Prefix OBU_METADATA_TYPE enum vals with "OBU_".

BUG=aomedia:1046

Change-Id: I0c63d36b77905520e427e6b77fbf4cbedabc7e51
diff --git a/aom/aom_codec.h b/aom/aom_codec.h
index 5e8b114..976c2b0 100644
--- a/aom/aom_codec.h
+++ b/aom/aom_codec.h
@@ -484,7 +484,7 @@
 /*!\brief OBU types. */
 typedef enum ATTRIBUTE_PACKED {
   OBU_SEQUENCE_HEADER = 1,
-  OBU_TD = 2,
+  OBU_TEMPORAL_DELIMITER = 2,
   OBU_FRAME_HEADER = 3,
   OBU_TILE_GROUP = 4,
   OBU_METADATA = 5,
@@ -493,10 +493,10 @@
 
 /*!\brief OBU metadata types. */
 typedef enum {
-  METADATA_TYPE_PRIVATE_DATA = 0,
-  METADATA_TYPE_HDR_CLL = 1,
-  METADATA_TYPE_HDR_MDCV = 2,
-} METADATA_TYPE;
+  OBU_METADATA_TYPE_PRIVATE_DATA = 0,
+  OBU_METADATA_TYPE_HDR_CLL = 1,
+  OBU_METADATA_TYPE_HDR_MDCV = 2,
+} OBU_METADATA_TYPE;
 
 /*!@} - end defgroup codec*/
 #ifdef __cplusplus
diff --git a/av1/av1_cx_iface.c b/av1/av1_cx_iface.c
index 2f361e1..e55625d 100644
--- a/av1/av1_cx_iface.c
+++ b/av1/av1_cx_iface.c
@@ -1331,7 +1331,8 @@
       memmove(ctx->pending_cx_data + PRE_OBU_SIZE_BYTES + 1,
               ctx->pending_cx_data, ctx->pending_cx_data_sz);
       obu_size = write_obu_header(
-          OBU_TD, 0, (uint8_t *)(ctx->pending_cx_data + PRE_OBU_SIZE_BYTES));
+          OBU_TEMPORAL_DELIMITER, 0,
+          (uint8_t *)(ctx->pending_cx_data + PRE_OBU_SIZE_BYTES));
       obu_size += write_temporal_delimiter_obu();
 #if CONFIG_ADD_4BYTES_OBUSIZE
       mem_put_le32(ctx->pending_cx_data, obu_size);
diff --git a/av1/decoder/decodeframe.c b/av1/decoder/decodeframe.c
index bd26aaa..eaad898 100644
--- a/av1/decoder/decodeframe.c
+++ b/av1/decoder/decodeframe.c
@@ -3865,16 +3865,16 @@
 }
 
 static size_t read_metadata(const uint8_t *data, size_t sz) {
-  METADATA_TYPE metadata_type;
+  OBU_METADATA_TYPE metadata_type;
 
   assert(sz >= 2);
-  metadata_type = (METADATA_TYPE)mem_get_le16(data);
+  metadata_type = (OBU_METADATA_TYPE)mem_get_le16(data);
 
-  if (metadata_type == METADATA_TYPE_PRIVATE_DATA) {
+  if (metadata_type == OBU_METADATA_TYPE_PRIVATE_DATA) {
     read_metadata_private_data(data + 2, sz - 2);
-  } else if (metadata_type == METADATA_TYPE_HDR_CLL) {
+  } else if (metadata_type == OBU_METADATA_TYPE_HDR_CLL) {
     read_metadata_hdr_cll(data + 2);
-  } else if (metadata_type == METADATA_TYPE_HDR_MDCV) {
+  } else if (metadata_type == OBU_METADATA_TYPE_HDR_MDCV) {
     read_metadata_hdr_mdcv(data + 2);
   }
 
@@ -3912,7 +3912,9 @@
     data += (PRE_OBU_SIZE_BYTES + obu_header_size);
 
     switch (obu_type) {
-      case OBU_TD: obu_payload_size = read_temporal_delimiter_obu(); break;
+      case OBU_TEMPORAL_DELIMITER:
+        obu_payload_size = read_temporal_delimiter_obu();
+        break;
       case OBU_SEQUENCE_HEADER:
         obu_payload_size = read_sequence_header_obu(pbi, &rb);
         break;